Plotting board



w K K oct. 11. 1927.

Qaoss REFERENCE l K. PETscHENlG t i' PLQTfrzNG BOARD Filed Aug. 25. 1926,

SEARCH Roon/'g l r l1 Patented Oct. 11, 1927.

' `run-1rEn STATES '.f

met Panorama or marne, Merate, Aerea@- "forraarra e @realer-f i TISCHE ANSTALT AKTIENGESELLSCHAFT, AKCIOVA, P.

'.r'IcxY UsfrAV, or nnairsiinva,foznoiiosnoynnrn' y grLofrriNG nonni).- I i P .ppncauon filed August 152s, semaine. leinwand nl mariana listas! 'The Vsubject matterof the present invenf' tion relates to that class ot apparatus by means otwhich, the distance-andthe lateral angle relatively to a predetermined direc- 5 tion (for instance lche north ,south ,direc- \.-.,ti on) required -for -iring by hidden .maehine guns or other ordnances at ltargets not 'directly visible to the gunners can.be-.determined, if lthe lateral angle- .and l.distance from a target-- are known, such angle ,and ,.dista-nce being determined byan observer stationed laterally of the point ot observation. p .Y

,llh'ile the constructions heretofore l5 knowna ,triangle geometric-ally similar ttof t-ively to `each otherf-.and .two horizontal ciroirlaigscales are neeessarypthe elements .of

thev triangle lare determined according .t9 the invention fby representing the .two known f sides-lof, thetriangle ,twolines alreadyV drawn fot two Y superposed parallel discs,

wvhereby any eccentricadjustment .is disposed with and a verysintpleand compacta, construction'is l` olotziinecli 1nwhich Ill parts are rotatable .around one andthe saine centre only one.1ule provided with scales or di- Visions and only one horizontal vcircular Scale or division being required.

A constructional form of the subject inatter of the invention is illustrated by way of example in the accompanying drawing. Fig. 1 is a section on a diameter ot the apparatus.

Fig. 2 is a plan view thereof. In the cylindrical bore of the ring l provided on its upper face with a horizontal 40 circular scale or division, a circular disc 2 serving as a base plate is rotatably mounted and carries in its centre a Vertical journal pin O, the handle O being preferably an extension ot such pin. On the upper tace A of the disc 2 there is drawna series ot' parallel lines` as indicated in full lines for better distinguishing them, they may either be drawn themselves in different colours or y the spaces between these lines may be in dif- '50 ferent colours. The line passing through the centre is provided with :in arrow head 2, A second circular disc 3 is adapted to 'ro'- tate freely in the ring l and relatively to the disc 2 is mounted directly above the set l rim ofthe base'disc 2. r

Yeiblei. @ed .-.c..3{.r.nuet ,betiiaesparent yand 1S. thereief. Preferably made Ot .cellulQId-f This disc 2 isv proyidedpnits- .bottonnside a terres,0f.parallel,lines,ied-Catedfnflottel.i .hase that .0f these lanes which passes.; thleaeh@ average. datation ,Ofi-fthe; projectile.

rel@ i .Servire im :'.letermnne the laterale .aegleef the andrew-0r aaneen-les. readfy i 111s' .mark i et .For lnflepeudelitlydecking kin p 5 position each-ot 'the 'discs'. relatively:Y to gt-hefg'lo st ructed Y for '-which purpose three; :rulesv provided K:with i scales and ad] ustable l rel-,n

. 111.10 parfaite te releer fh im at .the navet di illy-inthe rin-g may-be forced against the The liandlingofftliisapparatus o lowinfri lvfTlie `horizontal angle i1 Vbetween the observer target direction and the north south direction. f"

2, fl`he vhorizontal v angle between the observer gun direction and the direction north south by means of a compass.

3. The distance B Z between the observer and the target.

4. The distance B O between the observer ao and the gun measured by a range finder. Now after releasing the discs the adjustnient of the angle is eitected by the arrow' head 2a and the adjustment ot the angle by the arrow head 3a whereupon th-e set G5 screw 5 is screwed tight. 'l1lienbyta pencil.

on thev elluloiglwdisc" 3 wthe distance Z B-Z is marked on the line O 2a and the distance O B on the line 3a with the aid of the rotatable rule 4. Now the triusf 5 is found as the firing distance.

imagined to be drawn is likewise marked by a pencil and then the radial rule 4 is so turned that the deviation line passes through this point Z. Thus the sought distance O Z The reading mark ia of the radial rule is in the tangent of the centre of the deviation line and furnishes the lateral angle of the gun." L2

Of course, instead. of a curved radial rule,

i also a straight one might be used, the reading edge of which is exactlyl radial and forms the reading mark. But then obvious ly the lateral angle of thevgun so determined would have to be corrected for the deviation. Alsol the two central linesHO 2a and O 3a mi'g'ht be provided each with a distancescale "whereby the direct plotting of the "length O B and Z is rendered possible without "resorting tothe rotatable rule. V What I claim isz' i. In anapparatus or laying ordnance land machine guns or-indirectfiring, the combination of aY horizontal ring, there being a circular scale provided on such ring,

"-23 ahase dscnrovfledivith a series .QtSpfwd -parallel lines and a'transparent upper disc prvidefdwithu a seriesbf spaced parallel l i iie`s,v the said discs being mounted concen- 'trically on the said ring and being adapted 3a to rotate "'on such ring the one independently 2. In an apparatus for' laying ordnance and machine guns fori'ndirect firing, the combination of a horizontal ring, thereibe- 33 ing a circular scale providedon such ring,

a base disc provided with a series `of spaced parallel lines, and a transparentupper disc provided with a Iseries of spaced parallel parallel lines and a transparent upper disc provided with a seres of spaced parallel lines 'a base disc provided with a series of spaced and oi a rule provided with a longitudinal scale 'and a reading mark for cooperation with the circular scale, the, reading edge off' the rule being'laterally'oifset according to v{yt-lie average deviation angle,l the'said'discs 'and'the rule being mounted concentrically4 on the said ring and beingjadapted to ro-` tate on such ring the' one independently/,ot i ,'i Y. l ,ilwiio the other.

4. In an apparatus forlaying ordnance k and Amachine guns for indirect iiring,"the

combination of a horizontal ring, there bel ing a circular scale provided on such lr'ing,

a base disc provided with a seriesof spaced parallel lines anda transparent-upperdiscl provided with a series of vspaced parallel lines, the said discs being mounted c'oncen-'f trica-llyon the said ring and being 'adapted i to rotate on such' ring the 'one independently of the otherv and means for locking each of the said discs individually to the said ring.

In testimony whereof I'haves'igned my name to this specification.

KARL riarsciinivio. 

